1. Technical Field
The present invention relates to near-field scanning optical microscopes in general, and in particular to near-field scanning optical microscope probes. Still more particularly, the present invention relates to a near-field scanning optical microscope probe having a light emitting diode.
2. Description of Related Art
A near-field scanning optical microscope (NSOM) includes a probe designed to be placed close to the surface of a specimen in order to measure optical properties or expose light in a minute area of the specimen. The radius of curvature of the NSOM probe tip is less than the wavelength of light used for measurement. The resolution of a conventional NSOM is directly proportional to the size of its probe. For example, with an aperture probe, the resolving power is approximately 50 nm if the aperture diameter of its probe tip is 50 nm, and with a scattering probe, the resolving power corresponds to the order of the radius of curvature of its probe tip, which is approximately several tens of nanometers.
An NSOM probe is typically made of a pulled fiber optic. A densely-integrated probe array can dramatically increase scanning throughput, but since each probe within the probe array requires an external light source, the NSOM having a probe array tends to be more complex and bulky.
Other approaches for miniaturizing NSOM probes include the usage of probes having micro-electromechanical system (MEMS) apertures and probes having a light absorbing gold particle or a fluorescent bead at the probe tip. However, all those approaches still require an external light source, which lead to the same problem as mentioned above.
Consequently, it would be desirable to provide an improved NSOM probe.